From Running to HIIT and Strength Training: Kersten’s Story


Hey athletes,

I asked 12MA team member Kersten if she would share a little about her fitness background with you guys today because I found it super inspiring and thought it would resonate with a lot of you.

If you haven’t seen her around, she’s been writing some awesome and super helpful posts around here and she’s also the super awesome and supportive moderator in the 12MA Facebook group. You can find more of her on her site

Let’s hear her story:

Five years ago, I would’ve never thought that there will ever be a week when I run less than 10 miles. In my eyes, running was the only form of exercise and the only way to stay in shape. 

But things have changed and now my workouts last about 20-30 minutes. About a half of my workouts are done with bodyweight and half with weights, like kettlebells, sandbags etc. Running is still part of my HIIT workouts, but I no longer spend hours on the pavement.

Today I want to share how that happened and how my life has changed because of that.

But first, I want it to be clear that the goal of this post is not to say that nobody should ever run because it sucks so bad. In fact, I really don’t like how beating up running seems to be some strength coaches’ main goal.

I think that we should all do what we like best and what makes us happy, and if that’s running for you, then go for it. But know that running is not the only form of exercise and you don’t have to do it if you don’t like it. You may also re-think your running if you’re doing it for wrong reasons, like I did for several years.

The Reason I Started Running: Weight Loss

I’ve always been physically active, but running in particular became my main form of exercise about ten years ago. I wanted it to lose weight, and long distance running combined with a very restrictive, unhealthy diet helped me to lose 30 lbs. I got skinny, which back then was all that mattered to me.

I fell in love with the results I saw in my body and and soon realized that I should also try running on races. I trained smartly and was actually getting faster and faster.

I really enjoyed my long runs and started running marathons. Training was hard, but I’ve always loved hard workouts! My weekly mileage was usually between 40-45 miles, but on harder weeks even more.

However, while hitting a PR on my next marathon was important for me, keeping the weight off was as big, if not bigger reason why I ran so much. Eventually, my focus shifted purely to staying skinny. I stopped running shorter tempo runs because I thought more is better for my body (keeping the weight off). I didn’t care about the races that much anymore.

I got into this cycle where I had to constantly increase training volume and decrease the amount of food that I ate to stay skinny. But you can’t keep endlessly adding miles to your training. You need to mix things up and also do some strength training, work on your flexibility, mobility and so on. If you just keep running like I did, you end up constantly tired and never recovered for the next workout, which is exactly what happened to me.

Finding CrossFit

About 2.5 years ago the word CrossFit started to catch my eye in every fitness blog or social media account that I followed. I liked the competitive, don’t-leave-anything-in-the-tank nature of it, and I read a ton about how great results people got doing it. CrossFit workouts seemed way different than traditional gym / body building workouts that I never did because they bored me to death (they still would, if I had to do them).

However, there was no CrossFit box in the town I lived in, so all I could do was to look up a ton of CrossFit videos on Youtube and trying them out at the gym. By the time the first box was opened in my town and I did my first workout, I had already learned the basics of most olympic lifts and was probably the only one in the class who knew what a burpee was.

I absolutely loved pushing myself hard in CrossFit and was in love! I learned a lot of things that I had never even thought about:

  • Weight training is an awesome way to build muscle and get leaner physique. When I used to run, I was just skinny, but I had no muscle definition whatsoever.
  • A 10-minute workout made me working way harder than a 1-hour run ever did.
  • I learned a ton of fun bodyweight exercises and realized that I can do a super hard workout even without using any weights.
  • I found kettlebells–my main pieces of equipment that I now use in my training. If I could use just one workout tool for the rest of my life, that would be a kettlebell.

While I was going to CrossFit about 3 times a week, I also kept running about twice a week. I still loved it and being a strong runner was definitely advantage in CrossFit workouts too.

Transitioning to HIIT

However, about six months after starting CrossFit, I moved to another country and at the beginning, had no job. I was freshly certified personal trainer, but the market was super competitive and getting a job was tough. I simply couldn’t afford going to CrossFit.

What could I have done instead? Run? Yes, I could have. That would’ve been free.

But the thought of getting back to running 6 days a week wasn’t appealing to me anymore. I had already seen how weight training can save my time (hello, up to 30-minute workouts!), how my physique changed (hey, my shoulders look pretty defined!) and how much more I was looking forward to my workouts instead of being bored doing the same thing over and over again (variety is the key), I simply didn’t want to.

But I was broke and needed to find another way to workout that didn’t take $200 from my bank account every month.

I went to a store and bought a kettlebell.

Just one. I started working out with it and combined kettlebell training with running. About the same time, I also found 12 Minute Athlete and learned about those bodyweight workouts that were all done in minutes.

My typical morning–before I got back to job search–started with a 15-minute run or walk outside. After that, I did a 15-minute kettlebell HIIT or a 12 Minute Athlete bodyweight workout.

Even though I no longer had an access to a heavy barbell and other equipment I used to use at CrossFit, I soon realized that that’s absolutely fine. I was able to break a ton of sweat by pushing myself really hard with just 15-minute kettlebell or bodyweight HIIT workouts, and still keep the results.

Combining Strength Training and HIIT–and a Bit Of Running

At this point of my life, I’m combining HIIT and strength training, a little bit of running and lots of walking and bike riding. My main form of exercise is HIIT, and kettlebell and dumbbell HIIT workouts are my favorites.

I now know that weight training doesn’t have to mean counting long and tedious reps and spending two hours at the gym–most days, 20 minutes is enough. You also don’t have to spend hours every day running, unless you’re training for marathons. Especially if your goal is to burn more fat, lean out and gain strength, you don’t achieve that by only running.

Here are the main changes that have happened to me after changing my workouts from running 40-45 miles a week to doing HIIT and strength training and running about 10 miles a week.

  • I have way more time.
  • I’m much stronger.
  • I’m not hungry all the time. How’s that? When I was running, I was hungry all the time. But because I was afraid to eat and put on weight, I used to have a lot anxiety around food.
  • My workouts are more fun, because they’re different each time.
  • I’ve learned or I’m learning new skills–trying to do a handstand or pistol squats never crossed my mind before.
  • I became a trainer. 🙂 I now have much more to teach other people and help them with.


When I think back to my craziest running days, I see so many things that I was doing wrong. Maybe I knew it deep inside, but I didn’t want to admit it, because I thought that running is the only thing that is able to keep me in shape.

I still run sometimes and I would never tell anyone that running is stupid and that you should stop doing it immediately. Just know that if you’re running for wrong reasons–because you want to be skinny–there may be a better way to go. You probably want to be leaner, and for that, you need some strength training, with bodyweight or heavier weights. And if you really want to boost your fat burning, you’re probably better off doing a 15-minute HIIT instead of long cardio workouts.

Also, if your workouts are taking too much of your time (is your significant other hinting about it?) you may consider trying to work out on higher intensity, which significantly shortens your workout time.

Always keep in mind that it’s absolutely normal that your preferences change over the time. You don’t have to be a runner forever or weightlifter forever. Who knows, I may run another half or full marathon one day–never say never. But it’s important to be open minded about what else is out there and not to get stuck with your old routines if you feel that they no longer serve you.

Kersten Kimura is a NASM PT, kettlebell enthusiast and a fan of HIIT workouts. After relocating from chilly Estonia to California, she has taken full advantage of the area and works out outdoors whenever possible. You can find her throwing around her sandbag or swinging kettlebells at local parks, or sprinting along the gorgeous Bay Trail.

Find out more about Kersten here and sign up for her newsletter to get her one week equipment free workout plan and seven simple dinner recipes.

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12 thoughts on “From Running to HIIT and Strength Training: Kersten’s Story”

  1. Thank you for sharing your story Kersten! It is very inspiring. 🙂 I am nowhere near your fitness level but I learned early on that running for long hours could be not very good for you if you’re doing it wrong. I am currently following a weightlifting program for beginners, and after that I am looking to create my own program based on the exercises on your website. As you said, never say never. I’m looking forward to it already.

    • Awesome Andy! It doesn’t matter what your fitness level is now, as long as you do what you love, you keep moving forward. Creating your own program sounds awesome, because you can put it together from things that you like the best. Good luck!

  2. I totally get where you’re coming from Kersten! I too was in the running to maintain my weight frame of mind – for years I pounded the pavement without really ever considering there were alternative options out there. Then about 3 years ago I discovered Pilates/HIIT in the form of @blogilates and then @12minuteathlete and now I can’t imagine my life without these workouts. Super quick, effective, fun and varied, plus I’m not spending any $$ on gym memberships – just lots of workout clothes! Thanks for sharing Kersten and for all you guys do. Love it 🙂

    • Thanks Emma! I feel like we’re totally on the same page. Variety is so important, and HIIT and strength training and in your case pilates offer so much more of it than running. I still run in new places whenever I visit another city and it’s fun, but I wouldn’t want to do it everyday anymore. And you’re so right about workout clothes 😀 That and food is where my $$ go 😀

  3. Thanks for your story!! I like how you point out how running (unfairly) has become the go to strawman for a lot of HIIT advocates. It’s great how you are advocating for variety, sanity, balance, and most of all JOY in our fitness routines. I personally like to combine running with short effective strength routines. For me running provides the mental clarity I don’t get from the gym; but HIIT gives me her strength to be fit in all I do. Thanks!!

    • Hey Aaron, thanks! Running + strength is a perfect combination, I combine them a lot too. And I totally get what you mean by mental clarity you get from running. Long runs once in a while are almost meditative (but not anymore if you run hours and hours everyday), so I understand exactly what you mean!

  4. Great article! Your story is very inspiring…I am not near the fitness level I once was, but am working to get back there. I too did cross fit for several years, but became bored then could no longer afford it (after a job layoff) and I hated spending an hour or longer in the box. I too thought running was the only way to get back to my fitness level, but after being out of the CF gym for a few months I found that my endurance had suffered and I lacked motivation.
    I bought some equipment and do things on my own now…sometimes I walk in my neighborhood, or I do 12MA, lift weights or sometimes I just jump in my kids trampoline. I always change it up and I love the freedom of doing my own thing. Still working on my motivation…CF gyms offered great motivation from other members and I do miss that!

    • Hi Dawn, I think that it’s great that you have some equipment at home, that gives you the freedom to workout exactly the way you like. It’s good to think outside of a box (also Crossfit box 🙂 pun intended) and not to do only one thing, like CF or running or weight lifting. Any kind of moving is good, including jumping on your kids trampoline! I agree that motivation and support was a great part of Crossfit, but you CAN motivate yourself too once you get started.

  5. I love this article. It was fantastic! I am slowly realizing that I want to do more than just run all the time…especially with winter coming soon. Running outdoors in the snow gets hard! I’m also not seeing the weight loss I want with running and with a small child at home, I don’t have time for super long runs anymore. What is your typical workout schedule for a week? I’m just curious how you balance HIIT and strength training without being too fatigued to get a good workout in.

    • Hey Samantha! Thank you 🙂 For sure, it’s hard to make time for long runs if you have a little one at home or if you have a super busy schedule otherwise. I’m currently training 5-6 days a week and most of my workouts are 15-25 minutes. 2-3 of those workouts are bodyweight only and 3-4 with additional weights. You can find some examples on my site 🙂 I don’t do all-out type of HIIT more than 2-3 times a week, because while it’s very efficient, for me personally it’s a bit too demanding for my body. Let me know if you have other questions, I’m happy to help!

  6. Thanks kersten, I feel like I’m looking in the mirror when I read your story…..I’m a 79 year old Kettlebell instructor incorporating body weight exercises also….my classes are large and we all are getting in fantastic shape…..I utilize the “foam roller” and “stability ball” in the cool down phase of my class….I’ve found my “nitche”…..Regards, Wally Chute, Certified Fitness Instructor

    • Hey Wally! That sounds awesome, kettlebells are the best! Good to hear that you’ve found your niche. I like your cool down routine. I’m a fitness trainer myself too and often wish we had a little bit more time for a proper cool down at the end of the workout!


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